US20170274412A1 - Apparatus for coating catalyst slurry - Google Patents
Apparatus for coating catalyst slurry Download PDFInfo
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- US20170274412A1 US20170274412A1 US15/617,778 US201715617778A US2017274412A1 US 20170274412 A1 US20170274412 A1 US 20170274412A1 US 201715617778 A US201715617778 A US 201715617778A US 2017274412 A1 US2017274412 A1 US 2017274412A1
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- channels
- slurry
- coating apparatus
- air streams
- annular member
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- 239000002002 slurry Substances 0.000 title claims abstract description 108
- 239000011248 coating agent Substances 0.000 title claims abstract description 55
- 238000000576 coating method Methods 0.000 title claims abstract description 55
- 239000003054 catalyst Substances 0.000 title claims description 33
- 239000000758 substrate Substances 0.000 claims abstract description 101
- 230000001629 suppression Effects 0.000 claims description 12
- 239000000463 material Substances 0.000 claims description 10
- 239000006255 coating slurry Substances 0.000 claims description 3
- 125000006850 spacer group Chemical group 0.000 abstract description 20
- 238000007581 slurry coating method Methods 0.000 description 10
- 230000003247 decreasing effect Effects 0.000 description 8
- 230000000694 effects Effects 0.000 description 6
- 238000004519 manufacturing process Methods 0.000 description 6
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 4
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 4
- 238000000746 purification Methods 0.000 description 4
- 230000007423 decrease Effects 0.000 description 3
- 238000005259 measurement Methods 0.000 description 2
- 229910000510 noble metal Inorganic materials 0.000 description 2
- 229910052763 palladium Inorganic materials 0.000 description 2
- 229910052697 platinum Inorganic materials 0.000 description 2
- 238000004088 simulation Methods 0.000 description 2
- 230000004323 axial length Effects 0.000 description 1
- 238000009924 canning Methods 0.000 description 1
- 229910010293 ceramic material Inorganic materials 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 229910052878 cordierite Inorganic materials 0.000 description 1
- JSKIRARMQDRGJZ-UHFFFAOYSA-N dimagnesium dioxido-bis[(1-oxido-3-oxo-2,4,6,8,9-pentaoxa-1,3-disila-5,7-dialuminabicyclo[3.3.1]nonan-7-yl)oxy]silane Chemical compound [Mg++].[Mg++].[O-][Si]([O-])(O[Al]1O[Al]2O[Si](=O)O[Si]([O-])(O1)O2)O[Al]1O[Al]2O[Si](=O)O[Si]([O-])(O1)O2 JSKIRARMQDRGJZ-UHFFFAOYSA-N 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 229910052809 inorganic oxide Inorganic materials 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05C—APPARATUS FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05C5/00—Apparatus in which liquid or other fluent material is projected, poured or allowed to flow on to the surface of the work
- B05C5/02—Apparatus in which liquid or other fluent material is projected, poured or allowed to flow on to the surface of the work the liquid or other fluent material being discharged through an outlet orifice by pressure, e.g. from an outlet device in contact or almost in contact, with the work
- B05C5/027—Coating heads with several outlets, e.g. aligned transversally to the moving direction of a web to be coated
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05C—APPARATUS FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05C11/00—Component parts, details or accessories not specifically provided for in groups B05C1/00 - B05C9/00
- B05C11/02—Apparatus for spreading or distributing liquids or other fluent materials already applied to a surface ; Controlling means therefor; Control of the thickness of a coating by spreading or distributing liquids or other fluent materials already applied to the coated surface
- B05C11/06—Apparatus for spreading or distributing liquids or other fluent materials already applied to a surface ; Controlling means therefor; Control of the thickness of a coating by spreading or distributing liquids or other fluent materials already applied to the coated surface with a blast of gas or vapour
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/92—Chemical or biological purification of waste gases of engine exhaust gases
- B01D53/94—Chemical or biological purification of waste gases of engine exhaust gases by catalytic processes
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D67/00—Processes specially adapted for manufacturing semi-permeable membranes for separation processes or apparatus
- B01D67/0039—Inorganic membrane manufacture
- B01D67/0046—Inorganic membrane manufacture by slurry techniques, e.g. die or slip-casting
-
- B01J35/04—
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J35/00—Catalysts, in general, characterised by their form or physical properties
- B01J35/50—Catalysts, in general, characterised by their form or physical properties characterised by their shape or configuration
- B01J35/56—Foraminous structures having flow-through passages or channels, e.g. grids or three-dimensional monoliths
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
- B01J37/02—Impregnation, coating or precipitation
- B01J37/0215—Coating
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05C—APPARATUS FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05C7/00—Apparatus specially designed for applying liquid or other fluent material to the inside of hollow work
- B05C7/04—Apparatus specially designed for applying liquid or other fluent material to the inside of hollow work the liquid or other fluent material flowing or being moved through the work; the work being filled with liquid or other fluent material and emptied
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2255/00—Catalysts
- B01D2255/10—Noble metals or compounds thereof
- B01D2255/102—Platinum group metals
- B01D2255/1021—Platinum
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2255/00—Catalysts
- B01D2255/10—Noble metals or compounds thereof
- B01D2255/102—Platinum group metals
- B01D2255/1023—Palladium
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2258/00—Sources of waste gases
- B01D2258/01—Engine exhaust gases
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2323/00—Details relating to membrane preparation
- B01D2323/42—Details of membrane preparation apparatus
Definitions
- the present invention relates to an apparatus for coating slurry containing a catalyst material on a monolithic catalyst honeycomb substrate used for purifying the exhaust gas of an automobile.
- a purification apparatus using a monolithic catalyst is conventionally known as an apparatus for purifying the exhaust gas of an automobile.
- the monolithic catalyst includes a substantially cylindrical honeycomb substrate having a large number of parallel channels for permitting a gas to flow in one direction, and slurry containing a catalyst material is coated on the inner surfaces of the channels of the honeycomb substrate.
- the exhaust gas flowing through the circumferential channels does not pass as smoothly as the exhaust gas flowing through the central channels as viewed in the radial direction of the monolithic catalyst. For this reason, the exhaust gas purification effect is lower in the circumferential portions of the monolithic catalyst than in the central portion thereof.
- a resistive member such as a net member or a plate member is arranged on the slurry supply side of the honeycomb substrate in such a manner that the slurry flow is decelerated in the circumferential portions and consequently the slurry is provided more in the central portion than in the circumferential portions.
- agglomerates of such slurry may be mixed in the liquid slurry to be coated. If this happens, the agglomerates may enter and clog the channels. As a result, the monolithic catalyst may be degraded in performance and quality.
- an inorganic oxide included in the slurry acts as an abrasive, and the resistive member is abraded thereby. That is, the resistive member has to be replaced with a new one after a certain period of time. This also increases the manufacturing cost of the monolithic catalyst.
- an object of the present invention is to provide a catalyst slurry coating apparatus which enables a monolithic catalyst improved in quality and performance to be manufactured at low cost.
- a coating apparatus for coating catalyst slurry according to the present invention is coating slurry containing a catalyst material on inner surfaces of a plurality of channels which extend through a substrate in a first direction and are adjacent to one another.
- the coating apparatus comprising slurry supply means for supplying the slurry into the channels from one end of the substrate, as defined in the first direction, air stream generation means for generating air streams flowing through the channels from the one end of the substrate to another end, as defined in the first direction, such that the slurry supplied from the one end of the substrate by the slurry supply means flows from the one end of the substrate through the channels toward said another end and reaches an intermediate point, as defined in an overall length of the substrate, and air stream suppression means, arranged away from said another end of the substrate and facing downstream-side ends of first channels, as viewed in the first direction, for suppressing the air streams in the first channels such that the air streams in the first channels are slower than the air streams in second channels.
- FIG. 1 is a schematic view showing a coating apparatus according to an embodiment.
- FIG. 2 is a perspective view illustrating an example of a honeycomb substrate to be used in the coating apparatus depicted in FIG. 1 .
- FIG. 3 is a plan view illustrating an annular net member employed in the coating apparatus depicted in FIG. 1 .
- FIG. 4 is a plan view illustrating an annular plate employed in the coating apparatus depicted in FIG. 1 .
- FIG. 5 is a table illustrating a combination example of how the thickness of a spacer is varied using either the net member shown in FIG. 3 or the plate shown in FIG. 4 .
- FIG. 6 is a graph illustrating how the coat width difference of slurry is related, based on the table shown in FIG. 5 .
- FIG. 7 is a sectional view of an actual honeycomb substrate and illustrating an example of the coat width difference of FIG. 6 based on the table shown in FIG. 5 .
- FIG. 8 is a graph illustrating how the coat width difference of slurry varies when a parameter (an opening ratio) of the coating apparatus is changed.
- FIG. 9 is a graph illustrating how the coat width difference of slurry varies when a parameter (the diameter of a channel) of the coating apparatus is changed.
- FIG. 10 is a graph illustrating how the coat width difference of slurry varies when a parameter (a clearance) of the coating apparatus is changed.
- FIG. 11 is a graph illustrating how the coat width difference of slurry varies when a parameter (a suction wind speed) of the coating apparatus is changed.
- FIG. 12 is a graph illustrating how the coat width difference of slurry varies when a parameter (a suction time) of the coating apparatus is changed.
- FIG. 13 is a graph illustrating how the coat width difference of slurry varies when a parameter (the viscosity of slurry) of the coating apparatus is changed.
- FIG. 14 is a graph illustrating how the coat width difference of slurry varies when a parameter (the amount of slurry supplied) of the coating apparatus is changed.
- FIG. 15 is a perspective view illustrating another example of a honeycomb substrate to be used in the coating apparatus depicted in FIG. 1 .
- FIG. 16 is a sectional view illustrating a coat shape obtained when slurry is coated for the honeycomb substrate shown in FIG. 15 in the state where no resistive member is employed.
- FIG. 17 is a sectional view illustrating a coat shape obtained when slurry is coated for the honeycomb substrate shown in FIG. 15 in the state where a resistive member is employed.
- FIG. 1 is a schematic view showing an example of a coating apparatus 10 configured to coat slurry on the inner surfaces of channels of a honeycomb substrate 1 .
- the slurry contains, for example, a catalyst material for purifying the exhaust gas of an automobile.
- the catalyst material includes a noble metal such as platinum or palladium.
- the coating apparatus 10 of the embodiment is an apparatus for manufacturing a monolithic catalyst used for purify the exhaust gas of an automobile.
- the exhaust gas of an automobile provides different flow rate distributions, depending upon the type of automobile, when it is made to flow through the monolithic catalyst.
- the exhaust gas flows in different ways, depending upon the canning shape of the catalyst and the bent state of a pipe.
- the coating apparatus 10 of the present embodiment enables control of the slurry coat shape for the honeycomb substrate 1 .
- the honeycomb substrate 1 has a substantially cylindrical outer shape, and a plurality of channels 2 extending in the axial direction are defined inside the honeycomb substrate 1 .
- the channels 2 are indicated by solid lines for the sake of easy understanding though they cannot be viewed in actuality.
- the channels 2 extend in the axial direction and are arranged in parallel to one another. In the present embodiment, all the channels 2 have the same cross sectional area.
- the cross sectional shape of each channel 2 may be any desirable shape, including circular shape and hexagonal shape.
- the honeycomb substrate 1 may be fabricated using such a ceramic material as cordierite, or stainless steel.
- the coating apparatus 10 is provided with a support base 11 for supporting the axially lower end 1 b of the honeycomb substrate 1 .
- the support base 11 is hollow and functions as a wind box 12 .
- the top plate 11 a of the support base 11 has a circular opening 11 b communicating with the hollow section of the wind box 12 .
- a resistive member 5 air stream suppression means, such as the annular net (net member) 3 shown in FIG. 3 or the annular plate (plate member) 4 shown in FIG. 4 , is attached to the circumference of the opening 11 b .
- An annular spacer 6 (adjusting means) is arranged between the resistive member 5 and the lower end 1 b of the honeycomb substrate 1 in such a manner that the honeycomb substrate 1 is located at a position above the resistive member 5 , as viewed in FIG. 1 . That is, the distance between the resistive member 5 and the lower end 1 b of the honeycomb substrate 1 can be changed in accordance with the thickness of the spacer 6 .
- the coating apparatus 10 is provided with a blower 7 (air stream generation means) which evacuates the hollow section of the wind box 12 .
- a blower 7 air stream generation means
- compressed air may be supplied to the channels 2 from the upper end 1 a of the honeycomb substrate 1 to cause air streams flowing through the channels 2 .
- the blower 7 When the blower 7 is driven in the state where the honeycomb substrate 1 is set on the support base 11 , with the spacer 6 interposed, the hollow section of the wind box 12 is evacuated, causing a negative pressure in the opening 11 b . As a result, air flows through the channels 2 from the upper end 1 a of the honeycomb substrate 1 to the lower end 1 b thereof. Then, slurry is supplied from a funnel-shaped supply frame 8 (supply means) attached to the upper end 1 a of the honeycomb substrate 1 . The slurry is sucked into the channels 2 from the upper end 1 a of the honeycomb substrate 1 , and the inner surfaces of the channels 2 are coated with the slurry.
- a funnel-shaped supply frame 8 supply means
- the amount of slurry to be supplied is determined in such a manner that when all of the slurry supplied at one time is made to flow from the supply frame 8 into the channels 2 , the slurry reaches an intermediate point of the overall length of the channels 2 .
- the slurry does not flow out of the lower end 1 b of the honeycomb substrate 1 , and the resistive member 5 does not get wet with the slurry. Since the slurry is hardly wasted, the manufacturing cost can be lowered, accordingly.
- the spacer 6 has a circular opening 6 a having substantially the same diameter as the outer diameter of the honeycomb substrate 1 .
- the support base 11 has a circular opening 11 b having substantially the same diameter as the outer diameter of the honeycomb substrate 1 .
- the blower 7 is driven in the state where the resistive member 5 is not attached to the circumference of the opening 11 b of the support base 11 .
- the air in every channel 2 of the honeycomb substrate 1 flows at the same speed, and the slurry coat width is substantially the same for all channels 2 .
- the “slurry coat width” is intended to refer to the distance between the upper end 1 a of the honeycomb substrate 1 to a position which the slurry reaches.
- the blower 7 is driven and the slurry is supplied in the state (the state shown in FIG. 1 ) where the annular resistive member 5 is attached to the circumference of the opening 11 b of the support base 11 .
- the suction force with which the slurry is sucked into the channels 2 (first channels) located in the outer circumferential area 2 b radially outward of the honeycomb substrate 1 is weaker than the suction force with which the slurry is sucked into the channels 2 (second channels) located in the center area 2 a close to the radial center of the honeycomb substrate 1 .
- the slurry coat width differs between the channels 2 located in the center area 2 a of the honeycomb substrate 1 and the channels 2 located in the outer circumferential area 2 b.
- the resistive member 5 has an opening smaller than the outer diameter of the honeycomb substrate 1 and faces the channels 2 (first channels) located in the radially outward of the honeycomb member 1 , namely, the outer circumferential area 2 b .
- the opening 5 a of the resistive member 5 oppose to the channels 2 (second channels) located in the center area 2 a .
- the speed of the air flow is lower in the channels 2 located in the outer circumferential area 2 b which the resistive member 5 faces than in the channels 2 in the center area 2 a .
- the slurry coat width is shorter in the outer circumferential area 2 b than in the center area 2 a.
- the inventors measured the coat width difference, using different types of resistive members 5 (the net member 3 and the plate member 4 ) and spacers 6 having different thicknesses (the thickness of a spacer 6 is equal to the distance between the honeycomb substrate 1 and the resistive member 5 ), and examined how the types of resistive member 5 and the thickness of a spacer 6 had an effect on the coat width difference.
- An example of the combination between the types of resistive member 5 and the thicknesses of the spacers 6 is shown in FIG. 5 .
- the measurements of the coat width difference are shown in FIG. 6 .
- the outer diameter of the honeycomb substrate 1 103 mm
- the outer diameter of the resistive member 5 103 mm
- the inner diameter of the. opening 5 a 60 mm
- the solid component of the slurry 30%
- the viscosity 0.4 s ⁇ 1 . . . 4000 mPa ⁇ s
- the coating amount 250 g
- the wind speed of the air flow caused by the blower 7 was measured before the slurry was supplied.
- the honeycomb substrate 1 was coated with the slurry. After the slurry dried, the center of the honeycomb substrate 1 was cut in the longitudinal direction (first direction), and the coat width difference of the slurry was measured in practice.
- the coat width difference tended to increase when the distance (clearance) between the lower end 1 b of the honeycomb substrate 1 and the resistive member 5 (namely, the thickness of the spacer 6 ) was short, and tended to decrease when the distance was long.
- the results are attributable to the fact that the resistive member 5 provided close to the honeycomb substrate 1 slows the speed of the air streams at the exit of the channels 2 located in the outer circumferential area 2 b which the resistive member 5 faces.
- the coat width difference could be controlled by changing the distance between the lower end 1 b of the honeycomb substrate 1 and the resistive member 5 , namely, the thickness of the spacer 6 . That is, with respect to the channels 2 in the center area 2 a which faces to the opening 5 a and is not influenced by the resistive member 5 , the slurry coat width does not vary in accordance with the thickness of the spacer 6 . The coat width varies in accordance with the thickness of the spacer 6 only in the channels 2 in the outer circumferential area 2 b . It is also found that if the resistive member 5 is away from the honeycomb substrate 1 more than 30 mm, the slurry coat width remains substantially the same as the case where the resistive member 5 is not provided.
- the net member 3 is used as the resistive member 5 , it can be arranged in contact with the honeycomb member 1 , without using the spacer 6 . Where the plate 4 is used, it must be away from the lower end 1 b of the honeycomb substrate 1 . Even where the net member 3 is employed, it should not be arranged in contact with the lower end of the honeycomb substrate 1 .
- the honeycomb substrate 1 may be brought into contact with the net member 3 at a low speed (slowly) when the honeycomb substrate 1 is set. If this is done, however, the takt time is inevitably long, and the productivity lowers. It may be thought to make the net member 3 , using a material softer than the material of the honeycomb substrate 1 . If this is done, however, the net member 3 is not rigid and is easy to deform. Such a soft net member may not satisfactorily function as the resistive member 5 .
- the resistive member 5 (even where the net member 3 is used) is arranged at a position away from the lower end 1 b of the honeycomb substrate 1 .
- the distance between the lower end 1 b of the honeycomb substrate 1 and the resistive member 5 should be more than 0 mm and less than 30 mm. In practice, if the distance exceeds 15 mm, the coat width difference becomes 10 mm or less. Under the circumstances, the resistive member 5 should be away from the honeycomb substrate 1 , and the distance between them should desirably be 20 mm or less.
- the coat width difference is larger in the case where the plate 4 is employed than in the case where the net member 3 is employed, provided that the thickness of the spacer 6 is the same. This is attributable to the fact that the air can flow through the net member 3 , whereas the air cannot flow through the plate 4 . That is, the use of the plate member 4 as the resistive member 5 is effective in providing a comparatively large coat width difference. As can be seen in FIG. 6 (which illustrates the case where the net member 3 is employed as the resistive member 5 and the case where the plate 4 is employed as the resistive member 5 ), the coat width difference is larger in the case where the plate 4 is employed than in the case where the net member 3 is employed, provided that the thickness of the spacer 6 is the same. This is attributable to the fact that the air can flow through the net member 3 , whereas the air cannot flow through the plate 4 . That is, the use of the plate member 4 as the resistive member 5 is effective in providing a comparatively large coat width difference. As can be seen in FIG.
- the coat width difference is less than 5 mm, as shown in FIG. 6 .
- the net member 3 hardly functions as the resistive member 5 . That is, the net member 3 hardly functions as the resistive member 5 unless it has a mesh smaller than 200 mesh.
- the type of resistive member 5 (including the mesh of a net member) should be properly selected, and the thickness of the spacer 6 has to be properly determined.
- the slurry coat shape on the honeycomb substrate 1 can be changed in accordance with the shape of the resistive member 5 and the position at which the resistive member 5 is arranged in the plane orthogonal to the axial direction of the honeycomb substrate 1 .
- Parameters having an effect on the coat width difference include the clearance between the resistive member 5 and the honeycomb substrate 1 , the type of resistive member 5 , the opening ratio of the resistive member 5 (plate 4 ′), the diameter of the channels 2 of the honeycomb substrate 1 , the suction wind speed provided by the blower 7 , the suction time, the viscosity of the slurry, the amount of slurry coated, etc.
- a honeycomb substrate having a diameter of 103 mm and an axial length of 83 mm was set on the coating apparatus 10 , a plate 4 ′ (not shown) having a large number of openings (0.8 mm ⁇ ) was arranged at a position 3 mm away from the lower end 1 b of the honeycomb substrate 1 , slurry having a viscosity of 130 mPas was supplied in an amount of 180 g, and the blower 7 was operated such that the suction wind speed was 40 m/s and the suction time was 3 sec. A simulation was performed based on these basic conditions.
- the opening ratio of the plate 4 ′ (the ratio of the total area of the openings to the area of the plate 4 ′ without the opening 5 a ) was set at 30%.
- the coat width difference increases.
- the coat width difference decreases. If the opening ratio of plate 4 ′ is decreased and the amount of air following through the openings is decreased, the slurry coating portion on the channels 2 in the center area 2 a of the honeycomb member 1 and the slurry coating portion on the channels 2 in the outer circumferential area 2 b are known to form a steep step shape. If the opening ratio of plate 4 ′ is increased and the amount of air following through the openings is increased, the slurry coating portions are known to form a gentle step shape.
- the slurry coating portion on the channels 2 in the center area 2 a of the honeycomb member 1 and the slurry coating portion on the channels 2 in the outer circumferential area 2 b are known to form a steep step shape, and that if the clearance of the plate 4 ′ relative to the honeycomb substrate 1 is increased, the slurry coating portions are known to form a gentle step shape.
- the suction wind speed by the blower 7 is decreased, the air flows slowly in the channels 2 facing the opening 5 a as well, resulting in a small coat width difference. Conversely, if the suction wind speed by the blower 7 is increased, the air flows rapidly in the channels 2 facing the opening 5 a as well, resulting in a large coat width difference. If the suction wind speed by the blower 7 is decreased, the slurry coating portion on the channels 2 in the center area 2 a of the honeycomb member 1 and the slurry coating portion on the channels 2 in the outer circumferential area 2 b are known to form a gentle step shape, and that if that suction wind speed is increased, the slurry coating portions are known to form a steep step shape.
- the suction time of the blower 7 is short, the amount of air stream (the amount of flowing air) is small, resulting in a small coat width difference. Conversely, if the suction time of the blower 7 is long, the amount of air stream (the amount of flowing air) is large, resulting in a large coat width difference.
- the present embodiment enables the coat width difference between the center area 2 a of the honeycomb substrate 1 and the outer circumferential area 2 b of the honeycomb substrate 1 to be controlled at a desired value by simply adjusting the thickness of the spacer 6 for example. Accordingly, a monolithic catalyst improved in both quality and performance can be manufactured at lost cost and with a simple structure.
- the slurry coat width is controlled to be shorter in the outer circumferential area 2 b than in the center area 2 a , because the air tends to flow at a lower speed through the channels 2 of the outer circumferential area 2 b of the honeycomb substrate 1 than through the channels 2 of the center area 2 a .
- the air flow speed through the channels 2 of the outer circumferential area 2 b be equal to the air flow speed through the channels 2 of the center area 2 a .
- FIG. 15 shows an example of a honeycomb substrate 21 wherein the diameter of channels 22 of the center area 2 a is comparatively small and the diameter of channels 24 of the circumferential area 2 b surrounding channels 22 is comparatively large.
- This honeycomb substrate 21 has the same shape and dimensions as the above-described honeycomb substrate 1 , except that channels 22 of the center area 2 a and channels 24 of the outer circumferential area 2 b are different in diameter.
- 600 channels 22 are provided in a square of (1 inch ⁇ 1 inch)
- 400 channels 24 are provided in a square of (1 inch ⁇ 1 inch).
- the air can easily flow through the channels 24 in the outer circumferential area 2 b .
- the speed at which the air flows through the channels 22 in the center area 2 a and the speed at which the air flows through the channels 24 in the outer circumferential area 2 b can be made substantially the same.
- this honeycomb substrate 21 is set in the coating apparatus 10 without the resistive member 5 , and slurry is supplied, with an air stream generated in all channels 22 and 24 , the slurry flows more smoothly in the channels 24 of the outer circumferential area 2 b than in the channels 22 of the center area 2 a .
- the slurry coat width in the channels 24 of the outer circumferential area 2 b is greater than the slurry coat width in the channels 22 of the center area 2 a , as shown in FIG. 16 .
- the honeycomb substrate 21 depicted in FIG. 15 is set in the coating apparatus 10 together with the resistive member 5 , and slurry is supplied by operating the blower 7 , the slurry coat width in the channels 22 of the center area 2 a and the slurry coat width in the channels 24 of the outer circumferential area 2 b are substantially equal, as shown in FIG. 17 .
- the slurry coat width in the center area 2 a and the slurry coat width in the outer circumferential area 2 b can be made equal to each other by simply adjusting the thickness of the spacer 6 .
- the slurry coat widths of all channels 22 and 24 are made equal to one another by designing the cross sectional area of the channels 24 of the outer circumferential area 2 b to be 1.5 times as wide as the cross sectional area of the channels 22 of the center area 2 a . It should be noted, however, the optimal cross sectional area ratio can be changed in accordance with the opening ratio of the resistive member 5 or the thickness of the spacer 6 .
- the coating apparatus 10 of the present embodiment can be advantageously applied to an apparatus for manufacturing this type of monolithic catalyst.
- the coat width of the slurry applied from one end of the honeycomb substrate and the coating width of the slurry applied from the other end of the honeycomb substrate are related to each other, so that it is useful to control the coat widths.
- a resistive member such as a net member or a plate member
- the air flow speed through the channels is made different, depending upon where the channels are located.
- any means may be employed as a resistive member, as long as it can suppress the air flow through the channels in a state where it does not contact the slurry.
- the resistive member opposed to the honeycomb substrate was described as being annular, but the resistive member may have any shape as long as it can be opposed to channels where the slurry coat width should be decreased.
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Abstract
A coating apparatus includes: a supply frame for supplying slurry into channels from one end of a honeycomb substrate; and a blower for evacuating a wind box. An annular resistive member is attached to the circumference of the opening of the wind box, and the honeycomb substrate is arranged, with a spacer placed on the resistive member. When the blower is operated and the slurry is supplied, the coat width of the slurry coated on the inner surfaces of the channels in an outer circumferential area is less than the coat width of the slurry coated on the inner surfaces of the channels in a center area.
Description
- This application is a Continuation Application No. PCT/JP2016/057328, filed Mar. 9, 2016 and based upon and claiming the benefit of priority from Japanese Patent Application No. 2015-046249, filed Mar. 9, 2015, the entire contents of which are incorporated herein by reference.
- The present invention relates to an apparatus for coating slurry containing a catalyst material on a monolithic catalyst honeycomb substrate used for purifying the exhaust gas of an automobile.
- A purification apparatus using a monolithic catalyst is conventionally known as an apparatus for purifying the exhaust gas of an automobile. The monolithic catalyst includes a substantially cylindrical honeycomb substrate having a large number of parallel channels for permitting a gas to flow in one direction, and slurry containing a catalyst material is coated on the inner surfaces of the channels of the honeycomb substrate. When the exhaust gas flows through the channels of the monolithic catalyst in the axial direction of the honeycomb substrate, chemical reaction takes place between the exhaust gas and the catalyst material, and the exhaust gas is purified thereby.
- When the exhaust gas flows through the cylindrical monolithic catalyst, the exhaust gas flowing through the circumferential channels does not pass as smoothly as the exhaust gas flowing through the central channels as viewed in the radial direction of the monolithic catalyst. For this reason, the exhaust gas purification effect is lower in the circumferential portions of the monolithic catalyst than in the central portion thereof.
- In an effort to solve this problem, various measures are taken to improve the exhaust gas purification effect at the time of manufacturing the catalyst, such as coating a larger amount of slurry in the central portion of the honeycomb substrate than in the circumferential portions thereof. For example, in the coating apparatus disclosed in Jpn. Pat. Appin. KOKAI Publication No. 2009-136833, a resistive member such as a net member or a plate member is arranged on the slurry supply side of the honeycomb substrate in such a manner that the slurry flow is decelerated in the circumferential portions and consequently the slurry is provided more in the central portion than in the circumferential portions.
- However, where a resistive member is arranged on the slurry supply side of the honeycomb substrate, as in the coating apparatus disclosed in Jpn. Pat. Appin. KOKAI Publication No. 2009-136833, the slurry inevitably attaches to the resistive member and remains on it, resulting in an increase in the amount of slurry consumed. Since the catalyst material included in the slurry contains a noble metal such as platinum or palladium, the manufacturing cost of the monolithic catalyst increases in accordance with an increase of the amount of slurry consumed. In addition, if the slurry attaches to the resistive member ununiformly, the amount of slurry coated on the honeycomb substrate may also become ununiform, with the result that monolithic catalysts may vary in quality.
- If the slurry attaching to the resistive member dries and hardens, agglomerates of such slurry may be mixed in the liquid slurry to be coated. If this happens, the agglomerates may enter and clog the channels. As a result, the monolithic catalyst may be degraded in performance and quality.
- Where a resistive member is arranged on the slurry supply side, an inorganic oxide included in the slurry acts as an abrasive, and the resistive member is abraded thereby. That is, the resistive member has to be replaced with a new one after a certain period of time. This also increases the manufacturing cost of the monolithic catalyst.
- Accordingly, an object of the present invention is to provide a catalyst slurry coating apparatus which enables a monolithic catalyst improved in quality and performance to be manufactured at low cost.
- A coating apparatus for coating catalyst slurry according to the present invention is coating slurry containing a catalyst material on inner surfaces of a plurality of channels which extend through a substrate in a first direction and are adjacent to one another. The coating apparatus comprising slurry supply means for supplying the slurry into the channels from one end of the substrate, as defined in the first direction, air stream generation means for generating air streams flowing through the channels from the one end of the substrate to another end, as defined in the first direction, such that the slurry supplied from the one end of the substrate by the slurry supply means flows from the one end of the substrate through the channels toward said another end and reaches an intermediate point, as defined in an overall length of the substrate, and air stream suppression means, arranged away from said another end of the substrate and facing downstream-side ends of first channels, as viewed in the first direction, for suppressing the air streams in the first channels such that the air streams in the first channels are slower than the air streams in second channels.
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FIG. 1 is a schematic view showing a coating apparatus according to an embodiment. -
FIG. 2 is a perspective view illustrating an example of a honeycomb substrate to be used in the coating apparatus depicted inFIG. 1 . -
FIG. 3 is a plan view illustrating an annular net member employed in the coating apparatus depicted inFIG. 1 . -
FIG. 4 is a plan view illustrating an annular plate employed in the coating apparatus depicted inFIG. 1 . -
FIG. 5 is a table illustrating a combination example of how the thickness of a spacer is varied using either the net member shown inFIG. 3 or the plate shown inFIG. 4 . -
FIG. 6 is a graph illustrating how the coat width difference of slurry is related, based on the table shown inFIG. 5 . -
FIG. 7 is a sectional view of an actual honeycomb substrate and illustrating an example of the coat width difference ofFIG. 6 based on the table shown inFIG. 5 . -
FIG. 8 is a graph illustrating how the coat width difference of slurry varies when a parameter (an opening ratio) of the coating apparatus is changed. -
FIG. 9 is a graph illustrating how the coat width difference of slurry varies when a parameter (the diameter of a channel) of the coating apparatus is changed. -
FIG. 10 is a graph illustrating how the coat width difference of slurry varies when a parameter (a clearance) of the coating apparatus is changed. -
FIG. 11 is a graph illustrating how the coat width difference of slurry varies when a parameter (a suction wind speed) of the coating apparatus is changed. -
FIG. 12 is a graph illustrating how the coat width difference of slurry varies when a parameter (a suction time) of the coating apparatus is changed. -
FIG. 13 is a graph illustrating how the coat width difference of slurry varies when a parameter (the viscosity of slurry) of the coating apparatus is changed. -
FIG. 14 is a graph illustrating how the coat width difference of slurry varies when a parameter (the amount of slurry supplied) of the coating apparatus is changed. -
FIG. 15 is a perspective view illustrating another example of a honeycomb substrate to be used in the coating apparatus depicted inFIG. 1 . -
FIG. 16 is a sectional view illustrating a coat shape obtained when slurry is coated for the honeycomb substrate shown inFIG. 15 in the state where no resistive member is employed. -
FIG. 17 is a sectional view illustrating a coat shape obtained when slurry is coated for the honeycomb substrate shown inFIG. 15 in the state where a resistive member is employed. - Hereinafter, embodiments will be described in detail with reference to the accompanying drawings.
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FIG. 1 is a schematic view showing an example of acoating apparatus 10 configured to coat slurry on the inner surfaces of channels of ahoneycomb substrate 1. The slurry contains, for example, a catalyst material for purifying the exhaust gas of an automobile. The catalyst material includes a noble metal such as platinum or palladium. Thecoating apparatus 10 of the embodiment is an apparatus for manufacturing a monolithic catalyst used for purify the exhaust gas of an automobile. - The exhaust gas of an automobile provides different flow rate distributions, depending upon the type of automobile, when it is made to flow through the monolithic catalyst. In addition, the exhaust gas flows in different ways, depending upon the canning shape of the catalyst and the bent state of a pipe. In order to improve the exhaust gas purification effect, it is preferred that the coat shape of the slurry for the
honeycomb substrate 1 be changed in accordance with the type of automobile or the installation position of the catalyst. Thecoating apparatus 10 of the present embodiment enables control of the slurry coat shape for thehoneycomb substrate 1. - As shown, for example, in
FIG. 2 , thehoneycomb substrate 1 has a substantially cylindrical outer shape, and a plurality ofchannels 2 extending in the axial direction are defined inside thehoneycomb substrate 1. InFIG. 1 , thechannels 2 are indicated by solid lines for the sake of easy understanding though they cannot be viewed in actuality. Thechannels 2 extend in the axial direction and are arranged in parallel to one another. In the present embodiment, all thechannels 2 have the same cross sectional area. The cross sectional shape of eachchannel 2 may be any desirable shape, including circular shape and hexagonal shape. Thehoneycomb substrate 1 may be fabricated using such a ceramic material as cordierite, or stainless steel. - The
coating apparatus 10 is provided with asupport base 11 for supporting the axiallylower end 1 b of thehoneycomb substrate 1. Thesupport base 11 is hollow and functions as awind box 12. Thetop plate 11 a of thesupport base 11 has acircular opening 11 b communicating with the hollow section of thewind box 12. A resistive member 5 (air stream suppression means), such as the annular net (net member) 3 shown inFIG. 3 or the annular plate (plate member) 4 shown inFIG. 4 , is attached to the circumference of theopening 11 b. An annular spacer 6 (adjusting means) is arranged between theresistive member 5 and thelower end 1 b of thehoneycomb substrate 1 in such a manner that thehoneycomb substrate 1 is located at a position above theresistive member 5, as viewed inFIG. 1 . That is, the distance between theresistive member 5 and thelower end 1 b of thehoneycomb substrate 1 can be changed in accordance with the thickness of thespacer 6. - The
coating apparatus 10 is provided with a blower 7 (air stream generation means) which evacuates the hollow section of thewind box 12. Although theblower 7 is employed as the air stream generation means in the present embodiment, compressed air may be supplied to thechannels 2 from theupper end 1 a of thehoneycomb substrate 1 to cause air streams flowing through thechannels 2. - When the
blower 7 is driven in the state where thehoneycomb substrate 1 is set on thesupport base 11, with thespacer 6 interposed, the hollow section of thewind box 12 is evacuated, causing a negative pressure in theopening 11 b. As a result, air flows through thechannels 2 from theupper end 1 a of thehoneycomb substrate 1 to thelower end 1 b thereof. Then, slurry is supplied from a funnel-shaped supply frame 8 (supply means) attached to theupper end 1 a of thehoneycomb substrate 1. The slurry is sucked into thechannels 2 from theupper end 1 a of thehoneycomb substrate 1, and the inner surfaces of thechannels 2 are coated with the slurry. - The amount of slurry to be supplied is determined in such a manner that when all of the slurry supplied at one time is made to flow from the
supply frame 8 into thechannels 2, the slurry reaches an intermediate point of the overall length of thechannels 2. In other words, according to thecoating apparatus 10 of the embodiment, the slurry does not flow out of thelower end 1 b of thehoneycomb substrate 1, and theresistive member 5 does not get wet with the slurry. Since the slurry is hardly wasted, the manufacturing cost can be lowered, accordingly. - The
spacer 6 has acircular opening 6 a having substantially the same diameter as the outer diameter of thehoneycomb substrate 1. Likewise, thesupport base 11 has acircular opening 11 b having substantially the same diameter as the outer diameter of thehoneycomb substrate 1. Let us assume that theblower 7 is driven in the state where theresistive member 5 is not attached to the circumference of theopening 11 b of thesupport base 11. In this case, the air in everychannel 2 of thehoneycomb substrate 1 flows at the same speed, and the slurry coat width is substantially the same for allchannels 2. The “slurry coat width” is intended to refer to the distance between theupper end 1 a of thehoneycomb substrate 1 to a position which the slurry reaches. - According to the present embodiment, the
blower 7 is driven and the slurry is supplied in the state (the state shown inFIG. 1 ) where the annularresistive member 5 is attached to the circumference of theopening 11 b of thesupport base 11. In this case, the suction force with which the slurry is sucked into the channels 2 (first channels) located in the outercircumferential area 2 b radially outward of thehoneycomb substrate 1 is weaker than the suction force with which the slurry is sucked into the channels 2 (second channels) located in thecenter area 2 a close to the radial center of thehoneycomb substrate 1. As a result, the slurry coat width differs between thechannels 2 located in thecenter area 2 a of thehoneycomb substrate 1 and thechannels 2 located in the outercircumferential area 2 b. - The
resistive member 5 has an opening smaller than the outer diameter of thehoneycomb substrate 1 and faces the channels 2 (first channels) located in the radially outward of thehoneycomb member 1, namely, the outercircumferential area 2 b. Theopening 5 a of theresistive member 5 oppose to the channels 2 (second channels) located in thecenter area 2 a. With this structure, the speed of the air flow is lower in thechannels 2 located in the outercircumferential area 2 b which theresistive member 5 faces than in thechannels 2 in thecenter area 2 a. As a result, the slurry coat width is shorter in the outercircumferential area 2 b than in thecenter area 2 a. - In order to control the coat width difference (i.e., the difference between the slurry coat width in the outer
circumferential area 2 b and the slurry coat width in thecenter area 2 a) to be a desirable value, the inventors measured the coat width difference, using different types of resistive members 5 (thenet member 3 and the plate member 4) andspacers 6 having different thicknesses (the thickness of aspacer 6 is equal to the distance between thehoneycomb substrate 1 and the resistive member 5), and examined how the types ofresistive member 5 and the thickness of aspacer 6 had an effect on the coat width difference. An example of the combination between the types ofresistive member 5 and the thicknesses of thespacers 6 is shown inFIG. 5 . The measurements of the coat width difference are shown inFIG. 6 . - The other measurement conditions were determined as follows:
- the outer diameter of the honeycomb substrate 1: 103 mm
- the outer diameter of the resistive member 5: 103 mm, the inner diameter of the. opening 5 a: 60 mm
- the mesh of the net member 3: 250
- the solid component of the slurry: 30%, the viscosity: 0.4 s −1 . . . 4000 mPa ·s, the coating amount: 250 g
- the suction time by the blower 7: 5 sec, wind speed: 40 m/s
- The wind speed of the air flow caused by the
blower 7 was measured before the slurry was supplied. - Under the above conditions, the
honeycomb substrate 1 was coated with the slurry. After the slurry dried, the center of thehoneycomb substrate 1 was cut in the longitudinal direction (first direction), and the coat width difference of the slurry was measured in practice. - The results are shown in
FIG. 6 . As can be seen, it was found that in both the case where theplate 4 was employed as theresistive member 5 and the case where thenet member 3 was employed as theresistive member 5, the coat width difference tended to increase when the distance (clearance) between thelower end 1 b of thehoneycomb substrate 1 and the resistive member 5 (namely, the thickness of the spacer 6) was short, and tended to decrease when the distance was long. The results are attributable to the fact that theresistive member 5 provided close to thehoneycomb substrate 1 slows the speed of the air streams at the exit of thechannels 2 located in the outercircumferential area 2 b which theresistive member 5 faces. - In other words, it was found that the coat width difference could be controlled by changing the distance between the
lower end 1 b of thehoneycomb substrate 1 and theresistive member 5, namely, the thickness of thespacer 6. That is, with respect to thechannels 2 in thecenter area 2 a which faces to theopening 5 a and is not influenced by theresistive member 5, the slurry coat width does not vary in accordance with the thickness of thespacer 6. The coat width varies in accordance with the thickness of thespacer 6 only in thechannels 2 in the outercircumferential area 2 b. It is also found that if theresistive member 5 is away from thehoneycomb substrate 1 more than 30 mm, the slurry coat width remains substantially the same as the case where theresistive member 5 is not provided. - Where the
net member 3 is used as theresistive member 5, it can be arranged in contact with thehoneycomb member 1, without using thespacer 6. Where theplate 4 is used, it must be away from thelower end 1 b of thehoneycomb substrate 1. Even where thenet member 3 is employed, it should not be arranged in contact with the lower end of thehoneycomb substrate 1. - If the
net member 3 is in contact with thelower end 1 b of thehoneycomb substrate 1, it may happen that thehoneycomb substrate 1 will break or crack. To prevent thehoneycomb substrate 1 from breaking, thehoneycomb substrate 1 may be brought into contact with thenet member 3 at a low speed (slowly) when thehoneycomb substrate 1 is set. If this is done, however, the takt time is inevitably long, and the productivity lowers. It may be thought to make thenet member 3, using a material softer than the material of thehoneycomb substrate 1. If this is done, however, thenet member 3 is not rigid and is easy to deform. Such a soft net member may not satisfactorily function as theresistive member 5. - In the present embodiment, the resistive member 5 (even where the
net member 3 is used) is arranged at a position away from thelower end 1 b of thehoneycomb substrate 1. As described above, in order to provide the coat width difference, the distance between thelower end 1 b of thehoneycomb substrate 1 and theresistive member 5 should be more than 0 mm and less than 30 mm. In practice, if the distance exceeds 15 mm, the coat width difference becomes 10 mm or less. Under the circumstances, theresistive member 5 should be away from thehoneycomb substrate 1, and the distance between them should desirably be 20 mm or less. - As shown in
FIG. 6 (which illustrates the case where thenet member 3 is employed as theresistive member 5 and the case where theplate 4 is employed as the resistive member 5), the coat width difference is larger in the case where theplate 4 is employed than in the case where thenet member 3 is employed, provided that the thickness of thespacer 6 is the same. This is attributable to the fact that the air can flow through thenet member 3, whereas the air cannot flow through theplate 4. That is, the use of theplate member 4 as theresistive member 5 is effective in providing a comparatively large coat width difference. As can be seen inFIG. 6 , where theplate 4 is arranged at a position 1.8 mm away from thelower end 1 b of thehoneycomb substrate 1, the coat width difference is maximal, and the air stream can be suppressed most effectively. How the slurry is actually coated on thehoneycomb substrate 1 at the time is shown inFIG. 7 . - Where a comparatively-large-mesh
net member 3 having a mesh of 200 is arranged in contact with thelower end 1 b of thehoneycomb substrate 1, the coat width difference is less than 5 mm, as shown inFIG. 6 . In this case, thenet member 3 hardly functions as theresistive member 5. That is, thenet member 3 hardly functions as theresistive member 5 unless it has a mesh smaller than 200 mesh. - As should be clear from the above, in order to control the coat width difference, the type of resistive member 5 (including the mesh of a net member) should be properly selected, and the thickness of the
spacer 6 has to be properly determined. Needless to say, the slurry coat shape on thehoneycomb substrate 1 can be changed in accordance with the shape of theresistive member 5 and the position at which theresistive member 5 is arranged in the plane orthogonal to the axial direction of thehoneycomb substrate 1. - In the following, other conditions having an effect on the coat width difference will be considered. Parameters having an effect on the coat width difference include the clearance between the
resistive member 5 and thehoneycomb substrate 1, the type ofresistive member 5, the opening ratio of the resistive member 5 (plate 4′), the diameter of thechannels 2 of thehoneycomb substrate 1, the suction wind speed provided by theblower 7, the suction time, the viscosity of the slurry, the amount of slurry coated, etc. - As basic conditions, a honeycomb substrate having a diameter of 103 mm and an axial length of 83 mm was set on the
coating apparatus 10, aplate 4′ (not shown) having a large number of openings (0.8 mmφ) was arranged at aposition 3 mm away from thelower end 1 b of thehoneycomb substrate 1, slurry having a viscosity of 130 mPas was supplied in an amount of 180 g, and theblower 7 was operated such that the suction wind speed was 40 m/s and the suction time was 3 sec. A simulation was performed based on these basic conditions. The opening ratio of theplate 4′ (the ratio of the total area of the openings to the area of theplate 4′ without theopening 5 a) was set at 30%. The simulation result of the coat width difference obtained when the slurry was coated under the basic conditions was 13.6 mm. - How the coat width difference varied was examined by changing the parameters one by one. The results of examination are shown in
FIGS. 8 to 14 . - As shown in
FIG. 8 , the less the opening ratio of theplate 4′ is (i.e., the smaller the number of openings is), the smaller amount of air flowing through the openings of theplate 4′. As a result, the coat width difference increases. Conversely, the more the opening ratio of theplate 4′ is, the larger amount of air flowing through the openings of theplate 4′. As a result, the coat width difference decreases. If the opening ratio ofplate 4′ is decreased and the amount of air following through the openings is decreased, the slurry coating portion on thechannels 2 in thecenter area 2 a of thehoneycomb member 1 and the slurry coating portion on thechannels 2 in the outercircumferential area 2 b are known to form a steep step shape. If the opening ratio ofplate 4′ is increased and the amount of air following through the openings is increased, the slurry coating portions are known to form a gentle step shape. - As shown in
FIG. 9 , even if the openings of theplate 4′ are changed in diameter (with the opening ratio kept constant), the coat width difference remains substantially the same. - As shown in
FIG. 10 , if the clearance between thelower end 1 b of thehoneycomb substrate 1 andplate 4′ is decreased, the air does not flow smoothly through thechannels 2 facing theplate 4′. As a result, the coat width difference increases. Conversely, if the clearance between thelower end 1 b of the honeycombsubstrate land plate 4′ is increased, the air flows smoothly in thechannels 2 facing theplate 4′. As a result, the coat width difference decreases. If the clearance of theplate 4′ relative to thehoneycomb substrate 1 is decreased, the slurry coating portion on thechannels 2 in thecenter area 2 a of thehoneycomb member 1 and the slurry coating portion on thechannels 2 in the outercircumferential area 2 b are known to form a steep step shape, and that if the clearance of theplate 4′ relative to thehoneycomb substrate 1 is increased, the slurry coating portions are known to form a gentle step shape. - As shown in
FIG. 11 , if the suction wind speed by theblower 7 is decreased, the air flows slowly in thechannels 2 facing theopening 5 a as well, resulting in a small coat width difference. Conversely, if the suction wind speed by theblower 7 is increased, the air flows rapidly in thechannels 2 facing theopening 5 a as well, resulting in a large coat width difference. If the suction wind speed by theblower 7 is decreased, the slurry coating portion on thechannels 2 in thecenter area 2 a of thehoneycomb member 1 and the slurry coating portion on thechannels 2 in the outercircumferential area 2 b are known to form a gentle step shape, and that if that suction wind speed is increased, the slurry coating portions are known to form a steep step shape. - As shown in
FIG. 12 , if the suction time of theblower 7 is short, the amount of air stream (the amount of flowing air) is small, resulting in a small coat width difference. Conversely, if the suction time of theblower 7 is long, the amount of air stream (the amount of flowing air) is large, resulting in a large coat width difference. - As shown in
FIG. 13 , if the viscosity of the slurry is decreased, the air flows easily in thechannels 2 facing theopening 5 a, resulting in a large coat width difference. Conversely, if the viscosity of the slurry is increased, the air flows slowly in thechannels 2 facing theopening 5 a, resulting in a small coat width difference. - As shown in
FIG. 14 , even if the amount of slurry supplied is changed, the coat width difference remains substantially the same. - Provided that the above-mentioned parameters of the
coating apparatus 10 are set at appropriate values, the present embodiment enables the coat width difference between thecenter area 2 a of thehoneycomb substrate 1 and the outercircumferential area 2 b of thehoneycomb substrate 1 to be controlled at a desired value by simply adjusting the thickness of thespacer 6 for example. Accordingly, a monolithic catalyst improved in both quality and performance can be manufactured at lost cost and with a simple structure. - In the above-mentioned embodiment, the slurry coat width is controlled to be shorter in the outer
circumferential area 2 b than in thecenter area 2 a, because the air tends to flow at a lower speed through thechannels 2 of the outercircumferential area 2 b of thehoneycomb substrate 1 than through thechannels 2 of thecenter area 2 a. However, it is preferred that the air flow speed through thechannels 2 of the outercircumferential area 2 b be equal to the air flow speed through thechannels 2 of thecenter area 2 a. For this purpose, it is thought to increase the diameter of thechannels 2 of the outercircumferential area 2 b to be larger than the diameter of thechannels 2 of thecenter area 2 a. - In recent years, monolithic catalysts are being developed wherein the diameter of the
channels 2 of the outercircumferential area 2 b of thehoneycomb substrate 1 is larger than the diameter of thechannels 2 of thecenter area 2 a. -
FIG. 15 shows an example of ahoneycomb substrate 21 wherein the diameter ofchannels 22 of thecenter area 2 a is comparatively small and the diameter ofchannels 24 of thecircumferential area 2b surrounding channels 22 is comparatively large. Thishoneycomb substrate 21 has the same shape and dimensions as the above-describedhoneycomb substrate 1, except thatchannels 22 of thecenter area 2 a andchannels 24 of the outercircumferential area 2 b are different in diameter. To be more specific, in thecenter area 2 a, 600channels 22 are provided in a square of (1 inch×1 inch), and in the outercircumferential area 2 b, 400channels 24 are provided in a square of (1 inch×1 inch). - Where the diameter of the
channels 24 in the outercircumferential area 2 b is larger than the diameter of thechannels 22 in thecenter area 2a, the air can easily flow through thechannels 24 in the outercircumferential area 2 b. As a result, the speed at which the air flows through thechannels 22 in thecenter area 2 a and the speed at which the air flows through thechannels 24 in the outercircumferential area 2 b can be made substantially the same. - However, where this
honeycomb substrate 21 is set in thecoating apparatus 10 without theresistive member 5, and slurry is supplied, with an air stream generated in allchannels channels 24 of the outercircumferential area 2 b than in thechannels 22 of thecenter area 2 a. As a result, the slurry coat width in thechannels 24 of the outercircumferential area 2 b is greater than the slurry coat width in thechannels 22 of thecenter area 2 a, as shown inFIG. 16 . - In contrast, where the
honeycomb substrate 21 depicted inFIG. 15 is set in thecoating apparatus 10 together with theresistive member 5, and slurry is supplied by operating theblower 7, the slurry coat width in thechannels 22 of thecenter area 2 a and the slurry coat width in thechannels 24 of the outercircumferential area 2 b are substantially equal, as shown inFIG. 17 . In other words, as long as the above-mentioned parameters of thecoating apparatus 10 are set at respective appropriate values, the slurry coat width in thecenter area 2 a and the slurry coat width in the outercircumferential area 2 b can be made equal to each other by simply adjusting the thickness of thespacer 6. In the present embodiment, the slurry coat widths of allchannels channels 24 of the outercircumferential area 2 b to be 1.5 times as wide as the cross sectional area of thechannels 22 of thecenter area 2 a. It should be noted, however, the optimal cross sectional area ratio can be changed in accordance with the opening ratio of theresistive member 5 or the thickness of thespacer 6. - As another type of monolithic catalyst that comes to be put to practical use, different kinds of slurry (or the same kind of slurry) are coated from the respective axial ends of the honeycomb substrate. The
coating apparatus 10 of the present embodiment can be advantageously applied to an apparatus for manufacturing this type of monolithic catalyst. Where this type of monolithic catalyst is manufactured, the coat width of the slurry applied from one end of the honeycomb substrate and the coating width of the slurry applied from the other end of the honeycomb substrate are related to each other, so that it is useful to control the coat widths. - The embodiment described above does not limit the present invention and is presented by way of example. The scope of the invention is in no way restricted by the above-described embodiment. The above embodiment may be modified in various manners without departing from the gist of the invention.
- For example, in connection with the above embodiment, reference was made to the case where a resistive member, such as a net member or a plate member, is provided at a position away from the downstream-side end of the honeycomb substrate with respect to the slurry supply direction, and the air flow speed through the channels is made different, depending upon where the channels are located. However, this is not restrictive. Any means may be employed as a resistive member, as long as it can suppress the air flow through the channels in a state where it does not contact the slurry. In the above embodiment, the resistive member opposed to the honeycomb substrate was described as being annular, but the resistive member may have any shape as long as it can be opposed to channels where the slurry coat width should be decreased.
Claims (20)
1. A coating apparatus for coating slurry containing a catalyst material on inner surfaces of a plurality of channels which extend through a substrate in a first direction and are adjacent to one another, the coating apparatus comprising:
slurry supply means for supplying the slurry into the channels from one end of the substrate, as defined in the first direction;
air stream generation means for generating air streams flowing through the channels from the one end of the substrate to another end, as defined in the first direction, such that the slurry supplied from the one end of the substrate by the slurry supply means flows from the one end of the substrate through the channels toward said another end and reaches an intermediate point, as defined in an overall length of the substrate; and
air stream suppression means, arranged away from said another end of the substrate and facing downstream-side ends of first channels, as viewed in the first direction, for suppressing the air streams in the first channels such that the air streams in the first channels are slower than the air streams in second channels.
2. The coating apparatus according to claim 1 , wherein the first channels and the second channels have an equal cross sectional area, and
the air stream suppression means causes the air streams in the first channels to be slower than the air streams in the second channels and thereby permits a slurry coat width on the inner surfaces of the first channels, as determined in the first direction, to be shorter than a slurry coat width on the inner surfaces of the second chanhels, as determined in the first direction.
3. The coating apparatus according to claim 2 , further comprising:
adjusting means for adjusting a distance between said another end of the substrate and the air stream suppression means so as to control a difference between the slurry coat width on the inner surfaces of the first channels and the slurry coat width on the inner surfaces of the second channels.
4. The coating apparatus according to claim, wherein the first channels are annularly arranged around the second channels, and
the air stream suppression means is an annular member facing the downstream-side ends of the first channels, as defined in the first direction.
5. The coating apparatus according to claim 4 , wherein the annular member is a plate member that prevents air streams from flowing therethrough.
6. The coating apparatus according to claim 4 , wherein the annular member is a net member that permits air streams to flow therethrough.
7. The coating apparatus according to claim 1 , wherein the first channels have a cross sectional area wider than that of the second channels,
the air stream suppression means causes the air streams in the first channels to be slower than the air streams in the second channels and thereby permits a slurry coat width on the inner surfaces of the first channels, as determined in the first direction, to be equal to a slurry coat width on the inner surfaces of the second channels, as determined in the first direction.
8. The coating apparatus according to claim 7 , further comprising:
adjusting means for adjusting a distance between said another end of the substrate and the air stream suppression means such that the slurry coat width on the inner surfaces of the first channels and the slurry coat width on the inner surfaces of the second channels become equal to each other.
9. The coating apparatus according to claim 7 , wherein the first channels are annularly arranged around the second channels, and
the air stream suppression means is an annular member facing the downstream-side ends of the first channels, as defined in the first direction.
10. The coating apparatus according to claim 9 , wherein the annular member is a plate member that prevents air streams from flowing therethrough.
11. The coating apparatus according to claim 9 , wherein the annular member is a net member that permits air streams to flow therethrough.
12. The coating apparatus according to claim 2 , wherein the first channels are annularly arranged around the second channels, and
air stream suppression means is an annular member facing the downstream-side ends of the first channels, as defined in the first direction.
13. The coating apparatus according to claim 12 , wherein the annular member is a plate member that prevents air streams from flowing therethrough.
14. The coating apparatus according to claim 12 , wherein the annular member is a net member that permits air streams to flow therethrough.
15. The coating apparatus according to claim 3 , wherein the first channels are annularly arranged around the second channels, and
air stream suppression means is an annular member facing the downstream-side ends of the first channels, as defined in the first direction.
16. The coating apparatus according to claim 15 , wherein the annular member is a plate member that prevents air streams from flowing therethrough.
17. The coating apparatus according to claim 15 , wherein the annular member is a net member that permits air streams to flow therethrough.
18. The coating apparatus according to claim 8 , wherein the first channels are annularly arranged around the second channels, and
air stream suppression means is an annular member facing the downstream-side ends of the first channels, as defined in the first direction.
19. The coating apparatus according to claim 18 , wherein the annular member is a plate member that prevents air streams from flowing therethrough.
20. The coating apparatus according to claim 18 , wherein the annular member is a net member that permits air streams to flow therethrough.
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JP2015-046249 | 2015-03-09 | ||
JPJP2015-046249 | 2015-03-09 | ||
JP2015046249A JP6546758B2 (en) | 2015-03-09 | 2015-03-09 | Catalyst slurry coating system |
PCT/JP2016/057328 WO2016143811A1 (en) | 2015-03-09 | 2016-03-09 | Catalyst slurry coating device |
Related Parent Applications (1)
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PCT/JP2016/057328 Continuation WO2016143811A1 (en) | 2015-03-09 | 2016-03-09 | Catalyst slurry coating device |
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US20170274412A1 true US20170274412A1 (en) | 2017-09-28 |
US10160002B2 US10160002B2 (en) | 2018-12-25 |
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US15/617,778 Active US10160002B2 (en) | 2015-03-09 | 2017-06-08 | Apparatus for coating catalyst slurry |
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US (1) | US10160002B2 (en) |
JP (1) | JP6546758B2 (en) |
CN (2) | CN107107051A (en) |
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Cited By (2)
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US10328387B2 (en) | 2016-07-27 | 2019-06-25 | Cataler Corporation | Method and apparatus of manufacturing exhaust gas-purifying catalyst |
WO2020165387A1 (en) | 2019-02-14 | 2020-08-20 | Umicore Ag & Co. Kg | Method for producing motor vehicle exhaust gas catalysts |
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CN110711682B (en) * | 2019-10-18 | 2023-10-03 | 浙江达峰汽车技术有限公司 | Gasoline engine particulate matter filters carrier catalyst coating device |
CN117043124A (en) * | 2021-03-18 | 2023-11-10 | 三井金属矿业株式会社 | Apparatus and method for manufacturing structure |
DE202021106828U1 (en) | 2021-12-15 | 2023-03-24 | Umicore Ag & Co. Kg | coating chamber |
JP7455941B1 (en) | 2022-12-13 | 2024-03-26 | 株式会社キャタラー | Equipment for catalyst coating equipment and catalyst coating equipment |
DE202023103234U1 (en) | 2023-06-13 | 2023-06-26 | Umicore Ag & Co. Kg | coating device |
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JPS6012136A (en) * | 1983-07-04 | 1985-01-22 | Toyota Motor Corp | Coating and supporting method of monolithic carrier |
JPS60216848A (en) * | 1984-04-10 | 1985-10-30 | Toyota Motor Corp | Preparation of monolithic catalyst |
JPS63141648A (en) * | 1986-12-05 | 1988-06-14 | Toyota Motor Corp | Production of catalyst for cleaning exhaust gas of internal combustion engine |
JP3804850B2 (en) * | 1999-01-18 | 2006-08-02 | 日産自動車株式会社 | Monolith catalyst manufacturing equipment for exhaust gas purification |
JP2004141703A (en) * | 2002-10-22 | 2004-05-20 | Nissan Motor Co Ltd | Method for coating catalyst component and apparatus for coating catalyst component by using the method |
US8302557B2 (en) * | 2005-07-07 | 2012-11-06 | Cataler Corporation | Device and method for coating base material |
JP2007268484A (en) * | 2006-03-31 | 2007-10-18 | Toyota Motor Corp | Coating method of honeycomb substrate |
JP2009136833A (en) * | 2007-12-10 | 2009-06-25 | Toyota Motor Corp | Method for producing monolithic catalyst for exhaust gas cleaning and monolithic catalyst |
CN101734946B (en) * | 2009-12-18 | 2012-05-23 | 广东工业大学 | Method for applying coating on cordierite honeycomb ceramics and applications thereof |
GB201000019D0 (en) * | 2010-01-04 | 2010-02-17 | Johnson Matthey Plc | Coating a monolith substrate with catalyst component |
DE102010007499A1 (en) * | 2010-02-09 | 2011-08-11 | Umicore AG & Co. KG, 63457 | Volumetric coating arrangement |
KR101271434B1 (en) * | 2011-09-29 | 2013-06-10 | 희성촉매 주식회사 | Metered weight coater for precise PM control |
CN104324726B (en) * | 2014-10-13 | 2016-08-10 | 上海大学 | A kind of preparation method of metallic carrier integral catalyzer |
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2015
- 2015-03-09 JP JP2015046249A patent/JP6546758B2/en active Active
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Cited By (5)
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US10328387B2 (en) | 2016-07-27 | 2019-06-25 | Cataler Corporation | Method and apparatus of manufacturing exhaust gas-purifying catalyst |
WO2020165387A1 (en) | 2019-02-14 | 2020-08-20 | Umicore Ag & Co. Kg | Method for producing motor vehicle exhaust gas catalysts |
DE102019103765A1 (en) * | 2019-02-14 | 2020-08-20 | Umicore Ag & Co. Kg | Process for the production of catalytic converters for cars |
US20220134324A1 (en) * | 2019-02-14 | 2022-05-05 | Umicore Ag & Co. Kg | Method for producing motor vehicle exhaust gas catalysts |
DE102019103765B4 (en) | 2019-02-14 | 2023-01-12 | Umicore Ag & Co. Kg | Process for the production of automotive exhaust gas catalysts |
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Publication number | Publication date |
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US10160002B2 (en) | 2018-12-25 |
CN107107051A (en) | 2017-08-29 |
JP2016165673A (en) | 2016-09-15 |
CN111013938A (en) | 2020-04-17 |
JP6546758B2 (en) | 2019-07-17 |
WO2016143811A1 (en) | 2016-09-15 |
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